Each of JP2008-120324A and JP2009-61845A (which will be hereinafter referred to as References 1 and 2) discloses a known vehicle bumper apparatus to which a known crush box is applied (the crush box disclosed in Reference 1 is referred to as an energy absorbing member). The vehicle bumper apparatus is configured so that a bumper reinforcement member is supported by the crush box and mounted thereby to a side member of a vehicle body of a vehicle (for example, the crush box is crushed by a collision of the vehicle and therefore absorbs an impact energy generated by the collision).
According to References 1 and 2, the crush box of the vehicle bumper apparatus is configured to stably obtain an impact energy absorbing load (i.e., a load for absorbing an impact energy). However, the crush box disclosed in each of References 1 and 2 may not be configured in consideration for unexpected variations, for example, external disturbances or errors in design, so as to be resistant to such variations (that is, the crush box of each of References 1 and 2 is not configured so as to secure robustness).
A need thus exists for a crush box and a vehicle bumper apparatus, which are not susceptible to the drawbacks mentioned above.